Combination throttle and shift control



Nov. 11, 1952 J. F. MILLER COMBINATION THROTTLE AND SHIFT CONTROL 4 Sheets-Sheet 1 Filed April 5, 1950 P:55.55.5 i. .iiitih JOSEPH E M462,

1N VEN TOR.

2 4 M aw Nov. 11, 1952 J. F. MILLER 2,617,311

COMBINATION THROTTLE AND SHIFT CONTROL Filed April 5, 1950 4 Sheets-Sheet 2 I L I ee 7 e7 90 88 9 79 O O78\ 8| 60- 75 Q o 0 77 (/OSEPH E Muse,

7 Q INVENTOR.

y BY I Nov. 11, 1952 J. F. MILLER COMBINATION THROTTLE AND SHIFT CONTROL 4 Sheets-Sheet 5 Filed April 5, 1950 INVENTOR.

JOSEPH y fw prrae s s Nov. 11, 1952 J. F. MILLER 2,617,311

COMBINATION THROTTLE AND SHIFT CONTROL III JOS'L-PH E Muse INVEN TOR.

xtion.

Patented Nov. 11, 1952 UNITED stares Parser orFIcE 7,3 1 COMBINATION THROTTLE AND SHIFT CONTROL Joseph F. Miller, Alhambra, Calif as signorlof one-fourth to Karl F. Weikel, Long Beach,

icaur.

Application April 3, 1950, "SerialN'o: 153,694

Thisinventionrelates to a combination throttle and'shift tcontrol. suitable for use in conjunction with marine-"engines havingforward and reverse transmissions operable by transmissionlevers.

In some types of marine-engine installations the constructions are so heavy that power is required to effect a throwing 'ofthe-transmission lever 'into :forward or reverse positions or to return the transmission lever'into a neutral posi- =In .other installations the control lever which causes-ashiftingof the'itransmission lever is remotely'flocated from the transmission and iiunctionsinot only 'as a means .for controlling the shifting of the transmission lever but also as-a throttle control governing the speed of the :engine; :Difierent'I makes of .marine engines having forward and reverse transmissions have transmission levers that have difierent throws and considerable differences in'the' resistance to their movement'in' shifting from neutral to a forward position or: from neutral to i a I reverse position or from either extreme position to neutral. The amount of throw of the transmission lever from one'position 'to another may vary in length and the positions assumedby the lever'may also vary.

Whereap'ower means is used to efiect athrowing of the transmission lever from one position to another some "convenient means of adjustment is necessary' in order for the power means to be capable of being coupled to the transmission lever of various make's'of engines and function properly.

A primary object of the present invention is to'provide an improved 'combination throttle and shift control for marine engines' oi this character wherein a convenient means of adjustment is properly locaited s'othat the power means utilized -'to effect-"a shifting of thetransmission lever can be coupled to any-transmission lever regardless of itsilength of throw or the positions assumed thereby an'd by 'meansof the adjustment be caused'to functionproperly.

.Another object"oi' -theinvention'is to provide a shifting of the transmission as in ,the situation where itis. desired to merely warm' up theengine rapidly without placing it in either forward or .9 .Claims. (01. 7 m) form of "construction embodying the upon the line;3 3 upon Fig.1;

reverseigear or, on the other hand, the control lever can be used to effect a shifting of the transmission lever into either forward or reverse and after having accomplished the shifting at a low .or idling speed the control lever may then be used to control the speed of the engine while the boat is under way. A further feature of the design'is that a return of the control lever to its neutral position will automatically cut down the speed of the engine to its idling speed and also automatically return the transmission lever to its neutral position so that it is in effect impossible to shift, from forward position of the. transmission to reverse, or vice versa, without automatically reducing the engine speed to idling speed. 'In thismanner a protection for the propeller, its shaft and thrust bearing is afforded.

Still another object'of the invention is to. provide a construction wherein relatively simple connections between the Icontrol lever and the engine and the control lever of the transmission are possible, avoiding the use of a large number of .I'OdS, brackets, clevises and the like as in the conventional arrangement and which will also enable a control lever'for an engine and its transmission to be installed at more than one location such as, :for example, on the'flying bridge as well as in'the regular'cabin.

Another object of the invention is to provide a'construction which readily lends itself for use onboats equipped with twin engines and twin screws or propellers that will enable each engine and'its'transmission to be controlled in its operation by a single control lever. The control levers for the twinengines can be located'close together for convenience so that both levers canbe'readily operated by one hand of the pilot while the other hand .is being used by the pilot to manipulate the steering wheel.

'With the'foregoing .and other objects in view, which will 'be made manifest in the following detailed description and'specifically 'pointedout in the appended claims, reference i hadto' the accompanying drawings for an illustrativeembodiment of the invention, wherein;

Figure 1 is a diagrammatic view illustrating one form of construction embodying the present invention;

FigJZIiS a diagrammatic view of an alternative present invention; A V

Fig.,;3 is a sectional view taken substantially Fig.4 isa sectional view taken substantially upon the line 4-4 upon Fig.3;

Fig. 5 is a sectional view taken substantially upon the line 5-5 upon Fig. 1;

Fig. 6 is a sectional view taken substantially upon the line 66 upon Fig. 5;

Fig. 7 is a sectional view taken substantially upon the line 7-! upon Fig. 5;

Fig. 8 is a partial view in section taken substantially upon the line 8-8 upon Fig. 6;

Fig. 9 is a horizontal section taken upon the line 9-9 upon Fig. 6;

Fig. 10 is a view taken upon the line Ill-Ill upon Fig. 9 in the direction indicated;

Fig. 11 is a sectional view illustrating one form of connection that may be employed between a control lever and the throttle valve of the engine; and

Fig. 12 is a similar view but illustrating an alternative form of construction that may be employed to connect the control lever with the throttle valve of the engine.

Referring to the accompanying drawings wherein similar reference characters designate similar parts throughout, 10 indicates a marine engine having an intake manifold H to which fuel is supplied from a carburetor, the throttle valve of which is controlled by an arm or crank 12. Such a marine engine is usually equipped with a transmission i3 controlled by a transmission lever I4. In some forms of construction this transmission lever is located on the side of the transmission housing and is swung forwardly to connect the crank shaft of the engine with the drive or propeller shaft !5 so as to drive the propeller shaft in a forward direction. If the lever I4 is swung rearwardly the transmission connects the crank shaft of the engine with the propeller shaft l5 in such a manner as to drive the propeller shaft in a reverse direction. In other types of transmissions used on marine engines thetransmission lever, instead of being located on the side of the transmission housing, is located on the top thereof as shown in Fig. 2, and swings in a horizontal plane rather than in a vertical plane. As above explained, in different types of marine transmissions the length of throw of the lever I4 from a neutral position into a forward position may vary and likewise the length of throw from a neutral position into a reverse position may vary. The positions assumed by the lever I4 in any of the three operative conditions may likewise vary. It is desirable to be able to shift the lever M to or from either of the three positions by a remotely located control lever generally indicated at l5 that may be located on the bridge of the vessel or convenient to the pilots seat. Such a control lever on being moved forwardly can be used to first shift the transmission lever l4 forwardly and then may function to control the speed of the engine by shifting the position of the throttle lever or crank [2. Conversely, if it is desired to reversely operate the vessel on shifting the lever I 6 rearwardly the transmission lever [4 can be shifted into reverse position and the speed of the engine controlled by the lever l5 while the transmission is in reverse.

In that form of construction shown in Fig. 1, one form of power means is shown to effect a throwing of the transmission lever M. This is shown as consisting of a differential pressure motor having a cylinder l'l within which there is a piston IS, the piston rod [9 being pivotally connected to the transmission lever [4 as will be hereinafter explained. The ends of the cylinder I! communicate through passages and 2! with a manifold 22 that is connected by means of a con- 4 duit 23 to the intake manifold ll so as to utilize the vacuum or negative pressure in the manifold H as a source of power for operating the piston IS. The passages 20 and 21 are controlled by solenoid valves, generally indicated at 24 and 25. These valves are normally urged by springs 26 into positions wherein the passages 20 and 2| are closed to the manifold 22 but are open to atmosphere. However, when either solenoid 21 or 28 is energized its valve will be shifted to close the outlet to atmosphere and open its passage to the manifold 22 so that vacuum or negative pressure will be conducted to one end of the cylinder I! or the other. Thus if solenoid 27 is energized, vacuum or negative pressure from the intake manifold II will be conducted to the right hand end of cylinder I! and the atmospheric pressure in the left hand end of the cylinder is effective on the piston I8 to shift the transmission lever l4 forwardly. Conversely, if the solenoid 28 is energized the differential in pressure effective on the piston l8 serves to move the piston toward the left and thus swing the transmission lever [4 into reverse position. When either solenoid 21 or 28 is de-energized its spring 26 is effective to return the valve to the position shown wherein both ends of the cylinder I! are open to atmosphere and are disconnected from the manifold 22.

The details of the control lever 16 are illustrated in Figs. 5 to 10, inclusive. This consists of a suitable pedestal or housin 30 to one side of which there is secured a bushing 31. The bushing serves to rotatably support a shaft 32 carrying a crank 33 to which a pitman 34 may be connected. The outer end of the shaft 32 has a cap 35 mounted thereon and keyed thereto such as by a key 36. This cap carries a tubular arm or handle indicated at 31 within which there is disposed a brush or contactor 38. The brush or contactor carries a stem 39 that is surrounded by a compression spring 40 that is effective to urge a button 4| upwardly through the handle. This button has its lower end engageable with a pin 42 in the stem so as to normally lift the brush or contactor into the full line position shown in Fig. 6. A compression spring 43 is disposed between the interior of the bottom and the top of the stem 39 so that on depressing the button 4! the contactor or brush 38 may be moved downwardly or toward the center of the shaft 32 regardless of the pressure of the compression spring 40. The contactor will be pressed against contacts, hereinafter described, by the pressure of the compression spring 43.

Between the cap 35 and the flange of the bushing 3| there are insulating discs secured to the flange of the bushing and to the housing 30 such as by screws 44. On the outer face of the disc 45 there is a metallic member 46 which provides three contacts 41, 48 and 49 arranged adjacent the periphery of the disc, all of which are electrically connected together. This metallic member is equipped with a binding post 50 that is connected through a switch 5! (see Fig. 1) to a source of electric current such as, for example, the ignition primary circuit for the engine Ill. The switch 5| may be so arranged that on turnin on or completing the ignition primary circuit for the engine, switch 5| will automatically be closed to conduct electric current to the three contacts 41, 48 and 49. On the outer insulating disc 52 within the cap 35 there are three contacts arranged adjacent the periphery of that disc. These contacts are electrically insulated from each other and are disposed opposite the'*contacts'48;'41=and 49,";resp'ectively, across an'interveninginsulating disc'56. The edges of the contacts 41, 53,48 and Marc such that they may be engaged by the brush 'or contactor 33 when thatbrush or contactor isdepressed by the button 4| and the cap 35 is rotated with the shaft 32. Thusif the'handle-31 is swung in a counterclockwise direction'from the position shown in Fig. fiythe'brush or contactor 38 will establish an electrical connection between contacts 43 and 54. Contacts 49 and 55 are normally inelectrical contacts with each other through a springa'ctu'ate'd'brush 51 when the handle is in neutral position but when the handle is rotated from the neutral'position, shown in Fig. 6, the brush 51' will be carried to a position disengaging contacts'49 and 55.

Each of the contacts 53 and 54 has a binding post connected thereto, such binding posts being indicated at'58 and 59, the details of which are illustrated in Fig. 8. In a similar manner the contact 55 is equipped with a bindingpost ES. Spring-actuated detents 6| and 62 extend through'the discs and are partially receivable in depressions orsockets -63 that may be formed on th e'interior of the cap 35 to hold the cap and its handle in a position to which it may have been moved or shifted until forcibly displaced therefrom. Afiber friction disc 35ais disposed between the cap 35 and theinsulating discs to hold the cap frictionally in any position to which it may be set against creep due to vibration.

Binding post "53 is connected by a conductor '54 to a relay-65 that controls the circuit through. the solenoid 2?. In a similar manner binding post-59 isconnected by a conductor-66 to a relay 6? that controls the circuit through the solenoid 28." These relays are in-circuit with a relatively heavy 'source'of battery current supplied by the batteryb' 'and; in the preferred form of construction, thiscircu'it includes a thermostatic cutout 10 designed to automatically open the circuit through the relays after a predetermined length'of-time so that the heavy current supplied by'thebattery cannot continue'to flow through'the sole'n'oidsil or 28 continuously for longer 'than the predetermined length of time.

The 'th'ermostaticcutout is merely a protective measure for preventing the loading of'the solenoids 2! or '28 excessively. It' willthus be appreciated that, if the handle 31 is pushed forwardly and the button 4| is depressed, the circuit .through the relay "65 will be closed to energize thesolenoid 2! and thus cause the difierential pressuremotor to shift the transmission lever l4 forwardly. Convers'elyyif the handle 3'! is swun 'The 'binding post 60 which is on the contact 55 is'connected by; conductor H to contacts 72 and 13' (see Fig. 4) that are associated with the .pivotal connection between the piston rod l9 -andthetransrnission lever [4. As illustrated in 'Fig'. 3,-'the endofthe piston rod I9 is in the form of a 'clevisl4 which provides journals for a pivot pin 15' thatis keyed such as by a key 76 to the lever M. 'The-clevis also carries a housin 11 thatfsurroun'dsthe end of the pivot pin 15 that 'isshaped to provide a cam having two depres- "'sionstherein indicated at 'l8'and.'l9. The con- 'tacts'12 and l3 carry cam followers 89 and 8! 6 and are'spring-urged against the periphery (of the cam. These contacts are arranged opposite contacts 82 and 83, respectively, and in the neutral position of the transmission lever H the contacts 12 and '53 are held out of engagement with the contacts 32 and 83 as shown in Fig. 4. However, if the transmission lever It is swun forwardly the pivot pin :5, in turning with the lever, will eventually position the depression 79 opposite the cam follower 8i allowing the contacts E3 to engage the contact 83. Conversely, if the lever I5 is swung rearwardly, depression '58 will assume a position opposite the cam follower allowing contact i2 to engage contact 82. When the lever M returns from either of itsextremepositions to neutral the pivot pin and cam return to the position shown in Fig. 4 wherein all contacts within the housing ll are disengaged. Contact 83 is connected by a conductor as to conductor 555 which leadsto relay 6? and contact 82 is connected by a conductor 85 to conductor l5 which leads to relay 65. If it should be assumed that the control lever 16 has been swung forwardly while the button 4! is depressed to cause the transmission lever 54 to be shifted into its forward position, thismovement of the transmission lever serves to close contacts '83 and 83 preparing a circuit through relay 6? but not closing the circuit due to the fact that when the lever i5 is in its forward position there is no electrical connection through brush 5? across contacts as and 55. However, when the control lever i6 is returned to its neutral position, as shown in Fig. 6, brush 5? establishes electrical connection between contact ii! and contact 55 thus closing the circuit through contacts 73 and 83, actuating the relay 6? and operating the solenoid valve 25. This is efiective to supply vacuum or negative pressure to the left hand end of cylinder ll causing thepiston E8 to move from the right hand end of the cylinder toward the left. This movement continues until the lever it reaches its neutral position wherein the cam on the pivot pin 15 is in the position shown in Fig. 4. In this position the circuit through relaye'l is broken by the opening of contacts '73 and 83. Consequently when the control lever it returns to neutral the lever [4 will be returned to neutral and as soon as it reaches neutral position the circuit through relay El is open and the solenoid 22 is de-energized, stopping movement of the piston E8 in its neutral position. In a similar manner, if the control lever i5 is assumed as having been swung into the reverse position, lever i l will have been reversely swung causing the depression 78 to allow contacts 72 and 82 to engage and prepare the circuit through relay G5. On returning the control lever It to neutral, brush 5? completes the circuit thus prepared, returning the transmission lever Hi to neutral where it automatically stops by reason of the disengagement of the contacts 12 and 82.

A feature of the construction resides in the fact that the contacts i2 and 82 are both mounted on a section of insulating material, indicated at 85, that is circumierentially adjustable within the housing '57 by means of screws 37 extending through slots 88. In a similar manner, contacts 73 and 83 are mounted on a section of insulating material 89 that is likewise circumferentially adjustable by means of screws 98 extending through slots 9!. In this manner both sets of contacts associated with the pivotal connection between the piston rod l9 and the transmission lever I4 can be adjusted around the periphery of the cam. This adjustment of one set of contacts independently of the other is frequently quite important in that the exact positions when or where the contacts 'I282 and I3-83 open and close can be varied to meet the requirements of the throw or positions assumed by the lever I4 in each of its three operating positions, namely, forward, reverse and neutral.

In the event that the adjustment of the sections of insulation on which the contacts are mounted is insuflicient, the pivot pin I5 with its associated cam can be readily substituted or replaced to provide a cam with depressions I8 and I9 properly located. The ease with which such mission. For example, the control lever I6 may I be located on the flying bridge near the steering wheel thereon and a similar or identical control lever, indicated at I6a, may be located elsewhere such as, for example, in the regular cabin. This control lever may have its contacts or brushes electrically connected in parallel with the contacts or brushes of the control lever I6 so that either control lever may be used to close the electric circuits required to shift the lever I4 to its three positions.

Each control lever I5 and IBa is also capable of controlling the throttle valve of the engine III. Thus as illustrated in Fig. 5, the crank 33 is in its uppermost position when the control lever handle 31 is in its upright or neutral position. This crank has its pitman 34 engageable with a socket 92 in a piston 93 that is vertically reciprocable in a cylinder 94. This piston is urged by a compression spring 95 into its uppermost, position but when the control lever is swung either forwardly or rearwardly the pitman depresses the piston 93 against the action of the compression spring 95 and expels a liquid such as oil through a conduit 96 into a slave cylinder 91 located near the throttle valve crank or arm r I2. Within the slave cylinder 91 there is a piston 98 urged downwardly by a compression spring 99 and this piston has a piston rod I00 slidably extending through the head of a pivot bolt IIlI. The shank of this pivot bolt is pivotally mounted in the arm I2 and the slave cylinder itself is preferably pivoted as at I02. A collar I03 is adjustably mounted on the piston rod Hi0 and when the piston 98 is elevated this collar serves to force the throttle valve crank I2 upwardly. In the event that two control levers are employed indicated at IS and Ifia, the control lever I6a has a similar pitman operable upon a piston similar to the piston 93 and serving to expel liquid through a conduit 96a to a slave cylinder 91a wherein there is a piston having a piston rod that is also connected to the arm or crank I2 in the same manner. Consequently when the control lever [9a is operated the throttle valve of the engine may be opened by the control lever Ilia independently of the position of the other control lever. Whenever the throttle valve arm or crank I2 is elevated by the operation of the control lever IS the pivot bolt I0 Ia merely slides upwardly on the piston rod IBM and conversely whenever the crank I2 is elevated by the control lever I6a the pivot bolt IOI merely slides upwardly on the piston rod I00.

Surrounding the cylinder 94 there may be a jacket or reservoir I04 connected by small ports I05 to the cylinder 94 below the piston 93 when the piston is in its uppermost position. These ports permit air in the conduit 96 to escape up through the jacket I04 and serve also to maintain the conduit as well as the cylinder 94 filled with oil at all times.

An alternative form of construction for connecting the control levers to the throttle valve of the engine is illustrated in Fig. 12 wherein the pitman 34 is pivotally connected to a slide I06 in a cylinder or guide I01. This slide is connected by a wire I08 that is slidable in protective tubing I09 to the pivot bolt III], the end of the wire being slidable through the pivot bolt similar to the piston rod I00. A collar I I I is adjustable on the wire near its end and engages the pivot bolt in the same manner as the collar I03.

In the operation of the construction above described it will be appreciated that to shift the transmission lever I4 into its forward position the operator need merely depress the button 4I and swing the control lever I6 forwardly. The initial forward movement functions to close the circuit to throw the transmission lever I4 into its forward position and thereafter forward movement of the control lever I6 merely serves to control the throttle valve of the engine. It is unnecessary to keep the button 4I depressed after the initial forward movement. In a similar manner, if it is desired to operate the boat in reverse, the control lever I6 is swung rearwardly while the button 4| is depressed. The initial rearward movement closes the circuit to cause the lever I4 to be shifted into reverse position and thereafter the control lever I6 functions merely to control the throttle valve.

In Fig. 2 an alternative form of construction is disclosed wherein the transmission lever H4 is shown as being on top of the transmission housing and swingable in a horizontal plane. This lever has a rod I I5 pivotally connected thereto by a pivot pin similar to the pivot pin 15. The rod H5 is in turn connected to three cores or armatures H6, H1 and H8. These cores or armatures are spaced from each other by non-magnetic spacers or connectors H9 and I20. The spacing of the cores or armatures from each other is somewhat less than the spacing of their solenoids or windings I2 I, I22 and I23 in which they are respectively disposed. When winding I2I is energized it will tend to centralize its core or armature I I6 therein, causing the lever I I4 to be swung forwardly. Conversely, if the winding I23 is energized it will tend to centralize its armature or core I I8 therein, causing the lever I I4 to be swung rearwardly. When the lever I I4 is in either of its extreme positions and the winding I22 is energized, it will tend to centralize its core or armature and return the lever I I4 to neutral position. Relays I24, I25 and I26 control the circuits through the windings I 2I, I 22 and I23, respectively. Associated with the pivotal connection between the rod I I5 and the transmission lever I I4 there is a housing containing the contacts and cam similar to that illustrated in Figs. 3 and 4. However, in this form of construction the contacts 82 and 83 are connected together as indicated at I21 and the conductor leading therefrom indicated at I28 leads to the relay I25 that controls in this form of construction when the control lever has been moved forwardly to swing the transmission lever H4 forwardly-the closing of the -contacts1383 merely serves to prepare the circuit through the'relay I25; When the control lever is returned to neutral the circuit through the relay I25- is closed causing armature I I! to re.- turn the .transmission lever'l I4-to neutral. Similarly. if the control lever'has been shifted to reverse, the closing of the contacts'12-82 prepares the circuit through. the same relay I25 sothat when the control lever: is returned to neutral winding. I22 will be energized: and return the transmission lever to its neutral position:

In both forms of constructionit will beappreciated that-a power means is employed to shift thetransmission lever into its forward position or into its reverse: position that is controlled by the control lever which also functions as athrottle operator. The shifting, of the transmission lever into its forward position or reverse position prepares'the circuitwhich, when energizedby the returning of the control lever to'neutral, will enable the transmission lever to. be returnedto its a neutral position by the power means. In the form of construction shown in Fig. 1, the power means used to return the transmission lever from forward position to neutral is accomplished by the partial. operation of the reverse power means I whereas in that form of construction shownin Fig. 2, the power means'for returning' the transmission lever to neutral is the winding. I22 and its armature I I1. Inboth forms; of construction in. asmuch.as thecontacts-that prepare the circuits are associatedwith the pivotal connection betweenthe; transmission lever and its. operating rod, adjustments can'be easily madeito accommodate the construction to different transmissions havingv transmission levers whose throws may vary and: whose positions. in forward, neutral or reverse may vary.

In both forms of construction, if' the control lever is moved forwardly orrearwardly'from its central or neutral position withoutdepressing the button 4I,. the throttle valve. of "the engine. will merely be controlled to speed up? the engine without shifting the transmission from its neutral position. This is frequently-desirable when it is desired-towarm up the engne While the boat is still tied to'a' slip, float or mooring; If'it is desired to :propel the boat forwardly by the-engine, the control lever'is' movedforwardly. with the button 4| depressed which causes the transmission lever to be shifted while the engine. is operatingv at idling: speed. Thereafter the. continued movement of the control lever forwardly merely serves to speedup the engine. Thesame is true when the control lever is shifted rearwardly with the button 4| depressed. When the control lever is in either theforward or reverse position and is returned to its neutral position the transmission will be automatically returned to neutral whether the button 4| is depressed or not. Furthermore the connection with the throttle valve is such that the returnof the control lever to neutral automatically reduces the engine speed to idling. Consequently, if the control lever is shifted from a forward position through neutral to a reverse position with the button 4| depressed, the engine 10 speed-will be reduced to idling .speed in returning to neutral sothat in shifting the transmission to reverse this is performed while theengine is idling. The same sequence takes place in shifting the control-lever'from reverse position through neutral to a forward position.

The-improved arrangement also lends itself for use on boats having twin engines and twin screws, each engine being equipped with its own transmission. In such an event a control lever and its associated structure, as shown in Fig. 5, is merely duplicated on the left handside of the housing or pedestal 30 so that both levers are located quite close together andeither or both can be operated by a single hand of the pilot, leaving the otherhand free to manipulate the steering wheel. Where twin engines are employedI prefer to cross-connect'the conduit or tubing 23 andito equipeach tubing with a check valve such as that illustrated at I29. The purpose of such an arrangement is, briefly, as follows:

Vacuum created in themanifoldfi of one=engine can then be used'to operate its own differential pressure-motor orthe differential pressure'motor of the companion engine without the use of a vacuum tank. If oneengine is operating athigh speed or at wide open throttle, the vacuum in its manifold is'very low and if the other engine is operating at idling speed, the vacuum in its manifold is quite high. This high vacuum may be used to operate the differential pressure motor of its companion engine if the tubings 23 are cross-connected. The check valve I29 in each tubing 23 prevents flow from the manifold having low:vacuum into the tubing of the engine having the high vacuum.

From the above described construction it will be appreciated that the improved controlis highly advantageous in its simplicity of. construction, its ease of installation and ease of operation, requiring a minimum amount of attention from the pilot, effecting the desired speed'and' the desired shifting of the transmission.

Various changes may be made in the details of the construction without departing from the spirit and scope of the invention as defined by the appended claims.

1'. In combination, a marine engine having a forward and reverse transmission operable by a lever; power means forshifting the lever into a neutral position, a forward position or a reverse position, a control lever operatively connected to the engine to controlthe speed thereof, selector switchesassociated' withthe control lever and in circuit with the power means to cause the power means to shift the transmission lever into forward position when the control lever is shifted forwardly. and to. shift the transmission lever into reverse position when the control lever is shifted rearwardly, said switches including a neutral position switch adapted to be closed when the control'lever is in neutral position, and circuit-preparingswitches arranged at the connection betweenthe. power means and the trans mission lever in circuit with the neutral switch and'with the'power means arranged to be closed only'when the transmission lever is in its forward or, reverse position and to open when the transmission lever approaches its neutral position whereby when the control lever is positioned in neutral position after-having been in either forward or reverse position a circuit will be closed through the'power means toreturn the transmis- 11 sion lever to neutral and upon reaching neutral the circuit through the power means will be automatically opened.

2. In combination with a marine engine having a forward and reverse transmission operable by a lever, a shifting rod pivotally connected thereto for shifting said lever, power means for operating the shifting rod to shift the transmission lever into either forward, neutral or reverse positions, means forming a forward power circuit and a reverse power circuit, selector switches therefor, and means forming a neutral power circuit and a selector switch therefor, said neutral power circuit including circuit-preparing switches located at the connection bet-"een the transmission lever and shifting rod operable by the change in relative angularity between the shifting rod and said lever to open when the transmission lever is in neutral position and to close when the transmission lever is in an extreme position.

3. In combination with a marine engine having a forward and reverse transmission operable by a lever, a shifting rod pivotally connected thereto for shifting said lever, power means for operating the shifting rod to shift the transmission lever into either forward, neutral or reverse positions, means forming a forward power circuit and a reverse power circuit, selector switches therefor, and means forming a neutral power circuit and a selector switch therefor, said neutral power circuit including circuit-preparing switches located at the connection between the transmission lever and shifting rod operable by the change in relative angularity between the shifting rod and said lever to open when the transmission lever is in neutral position and to close when the transmission lever is in an extreme position, the positions at which the circuit-preparing switches are opened and closed being circumferentially adjustable with relation to the axis of pivot between the shifting rod and the transmission lever.

4. In combination with a marine engine having a forward and reverse transmission operable by a lever, a shifting rod pivotally connected thereto for shifting said lever, power means for operating the shifting rod to shift the transmission lever into either forward, neutral or reverse positions, means forming a forward power circuit and a reverse power circuit, selector switches therefor, and means forming a neutral power circuit and a selector switch therefor, said neutral power circuit including circuit-preparing switches located at the connection between the transmission lever and shifting rod operable by the change in relative angularity between the shifting rod and said lever to open when the transmission lever is in neutral position and to close when the transmission lever is in an extreme position, the positions at which the circuit-preparing switches are opened and closed being circumferentially adiustable independently of each other with relation to the axis of pivot between the sh fting rod and the transmission lever.

5. Circuit-preparing switches for use in conjunction with a power-operated shifting rod element and the transmission lever element of a marine engine having a forward and reverse transmission comprising a cam on one of said elements adapted to be rotated relative to the other in shifting the lever into either forward or reverse po ition, and. a pair of switches mounted on the other of said elements arranged to be operable by the cam so that one switch will be 12 closed when the transmission lever is in forward or reverse position and both will be open when the transmission lever is in neutral.

6. Circuit-preparing switches for use in conjunction with a power-operated shifting rod element and the transmission lever element of a marine engine having a forward and reverse transmission comprising a cam on one of said elements adapted to be rotated relative to the other in shifting the lever into either forward or reverse position, and a pair of switches mounted on the other of said elements arranged to be operable by the cam so that one switch will be closed when the transmission lever is in forward or reverse position and both will be open when the transmission lever is in neutral, each switch being adjustable about the periphery of the cam independently of the other so that the exact position of its opening and closing can be varied to compensate for different throws of different transmission levers.

'7. In combination with a marine engine having a forward and reverse transmission, a shifting rod pivotally connected to the lever of such transmission, armatures mounted on the shifting rod, solenoids for the armatures adapted when energized to centralize the armatures to shift the transmission into either forward, reverse or neutral positions, and circuits including selector switches for selectively energizing said solenoids and including preparatory switches located at the connection between the shifting rod and the transmission lever operable by a change in angularity therebetween for preparing a circuit through the neutral solenoid when the transmission lever is in one of its extreme positions.

8. In combination with a marine engine having a transmission operable by a lever capable of beng shifted into forward, reverse or neutral position, a shifting rod pivotally connected to said lever, a differential pressure motor for operating the shifting rod, solenoid valves controlling the pressure supplied to the motor to operate it in either direction, a control lever, selector switches associated therewith, and means providing circuits between the control lever, selector switches and the solenoid valves including circuit-preparing switches located at the connection between the shifting rod and the transmission lever for preparing a circuit through the solenoid valve controlling operation of the motor in, a reverse direction when the transmission lever is in its forward position and preparing a circuit through the solenoid valve controllingoperation of the motor in its forward direction when the transmission lever is in its reverse position. a

9. In combination with a marine engine having a forward and reverse transmission, a control lever movable forwardly or rearwardly from a neutral position, means operatively connecting the lever to the throttle of the engine to open the throttle as the lever is moved forwardly or reversely from the neutral position and allow the throttle to close to idling speed position when the control lever is returned to neutral position, power the transmission to neutral position whenever the control lever is returned to its neutral position.

JOSEPH F. MILLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Beemer June 15, 1909 Number 

